This application claims the priority of German application 196 30 647.7 filed in Germany on Jul. 30, 1996, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a MacPherson strut tower for a motor vehicle, especially a passenger car, connected to at least one adjoining side member of the body and permanently connected therewith.
German Patent Document DE-42 04 825 A1 teaches a MacPherson strut tower in the form of an extrusion-molded section for an automobile, with the extrusion-molded section surrounding an adjoining side member formwise at least for a portion of its length, and is additionally connected with the side member by gluing, welding, riveting, or the like.
This arrangement suffers from the disadvantage that the cutoff extrusion-molded section is made open on both sides in the lengthwise direction, so that it has only a low torsional stiffness in the direction of the axis of the MacPherson strut.
The linear connection of the MacPherson strut tower to a single side member and the welded seam, composed of sections running at angles to one another, are not optimal.
An object of the invention is to improve the MacPherson strut towers of a motor vehicle in such fashion that they can not only accept the forces transmitted by the chassis and conduct them into the adjoining body, but can also contribute to a significant increase in the stiffness of the supporting structure.
According to the invention, this object is achieved by providing an arrangement wherein the MacPherson strut tower is formed by a hollow body that is essentially closed and is produced by the internal high-pressure shaping method.
Principal advantages achieved with the invention consist in the fact that the MacPherson strut tower, formed by a one-piece hollow body that extends vertically and is essentially closed, is connected three-dimensionally to an upper side member and a lower side member, with the MacPherson strut tower contributing to a significant increase in rigidity, especially the torsional stiffness of the supporting structure. The hollow body is manufactured in a simple and economical fashion by internal high-pressure shaping. Annular connecting stubs provided endwise on the hollow body are supported externally in matching receptacles in the side members and are also permanently linked by welding with the adjoining side members, producing a welded seam without corners.
The hollow body, viewed in cross section, can have areas of different wall thickness, with the wall thickness being adaptable to the stresses that develop and thus contributing to weight optimization.
There is also a possibility of connecting the two MacPherson strut towers together in the upper area by a beam-like connecting part running crosswise, with the connecting part being made in one piece with the two MacPherson strut towers and produced by internal high-pressure shaping of a blank. This results in further stiffening of the supporting structure of the motor vehicle.